Page 373 - Biaxial Multiaxial Fatigue and Fracture
P. 373

Three-Dimensional Crack Growth: Numerical Evaluations and Experimental Tests   357

         hypotheses of linear elastic fracture mechanics (LEFM), which is not anymore applicable due to
         the strong plasticity effects. The automatically created and updated mesh is based on a variable
         number of  quadratic elements: 512 initially and 758 at the  last crack propagation step; it is
         visible, together with Von Mises stresses in Figs. 17-18.













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         Fig.  18. Von  Mises effective stresses on  an  magnified deformed plot  of  the plate  (the part-
         through crack opening is evident).

         Through-crack propagation. After the crack breaks-out on the opposite side (with respect to the
         notch position) of  the plate, an initial scenario obtained from experimental measurements was
         considered  for  the  simulation. The  related  results  are  presented  in  Figs.  19-21.  Again  the
         simulated propagation proceed a bit faster than the  experimental one.
         Again  the  crack  front  shapes  foreseen  by  the  simulation  are  well  in  agreement  with  the
         experimental ones (Fig. 22).






















         Fig. 19. Von Mises effective stresses on an magnified deformed plot of the plate (the through
         crack opening is evident).
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